Malicious PDF / .TXT — malware analysis report

Static analysis result for SHA-256 e4923f2a6100a25a…

MALICIOUS

PDF / .TXT

2.0 KB
MD5: f1121d37b47c9be78d8ee0f22f33c37d SHA-1: 41bd361e0dad0e1bfa37c306a410cd3b1718fbe7 SHA-256: e4923f2a6100a25a158d2d0c6c63b913a640c6d82fc4d23f0ee38254ec643fae
218 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The PDF file contains embedded JavaScript that utilizes `eval()` and `unescape()` functions, indicative of obfuscation. The critical heuristic CVE_2007_5659 specifically points to the exploitation of this CVE via the `Collab.collectEmailInfo` method. This suggests the primary function of the PDF is to exploit this vulnerability to execute arbitrary code, likely downloading and running a secondary payload. The presence of deobfuscated JavaScript further supports this analysis.

Heuristics 7

  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • ClamAV: Pdf.Exploit.Agent-35930 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35930
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj111611_000.js
f23e505f155bfa9b9f356fa9fddf8d7fcafcc37fc2df3878e575e72c00c819d4
pdf-javascript-stream PDF /JS object 111611 at offset 0x6D3 697 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
5695ad002ff2e5e296b09b880fe173c400f51eeb16222ed662f830e94edb51b0
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x189 2634 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).